Difference between RAD Model and Spiral Model

1. RAD Model :

RAD model refers to Rapid Application Development and it is a type of Incremental Model. The components or functions are developed in parallel and it can handle small projects as well as medium projects. In this model, any changes can be made at any stage. It has high productivity due to less number of people. 

2. Spiral Model :

Spiral Model is a software development life cycle model which is highly used for risk-driven models. Based on the risk patterns of a given project, the spiral model helps developers to increase the efficiency of the model as most risks are already handled. It consists of a number of loops which are forming a spiral shape where each loop is called the phase of the software development cycle. 

Difference between RAD Model and Spiral Model :

S.No.	RAD MODEL	SPIRAL MODEL
1.	RAD model is a software development model where by the components or functions are developed in parallel as if they were mini projects.	Spiral model is a software development model and is made with features of incremental, waterfall or evolutionary prototyping models.
2.	Rapid development is its main objective.	High assurance is its main objective.
3.	RAD model requirements and early stage planning is not necessary.	Spiral model requirements and early stage planning is required.
4.	It is necessary to have detailed documentation but in a limited manner.	Detailed documentation is required.
5.	Requirements are specified as time boxed release manner.	Requirements are specified in the beginning.
6.	RAD model is used between large and small project.	Spiral model is used for large project.
7.	There is low amount risk in RAD model.	There is medium to high amount risk in spiral model.
8.	In RAD model small team size is required.	In spiral model large team is required.
9.	Flexibility to change in RAD model is Easy.	Flexibility to change in spiral model is not that difficult.
10.	In RAD model overlapping of phases is possible.	In spiral model overlapping of phases is not possible.
11.	Testing is done in RAD model after completion of coding.	Testing is done in spiral model at the end of the engineering phase.
12.	Cost of RAD model is Low.	Cost of spiral model is very expensive.
13.	Customer involvement is only at the beginning.	Customer involvement is high as compared to RAD model.
14.	RAD model is having easy maintenance.	Spiral model has typical maintenance.
15.	It offers reusability.	Reusability is possible to some extent.